Heres what i know. It almost would be impossible for angel to give him the marks on his face, and even though jack says angel killed her mother, he was lying. She was put into control core angel before her mother left. Angels mother left because she couldn't stand what jack was doing to their little girl, so she left him with no hope to see her daughter again. The mothers whereabouts are unknown, but she is not dead. Thats a sure thing. Now, angel NOR yourself could give him the marks (yourself referring to the comment about how they think he got the marks by the final fight with you.) because even before he was president, before being handsome jack (originally named john (last name unknown)), and before he had his daughter, he worked as a Hyperion programmer, and still had worn the mask. Also, to prove that angel didnt kill her mother, when jack found out that she was a siren, immediately put her into the control core angel, so that he could control the ECHOnet and slowely rise up the hyperion ladder into becoming president by killing and blackmailing. When he became president, he changed his name to handsome jack to contradict him never really being attractive in the first place. My guess is that his grandmother was the one who gave him the scars. In the side quest where you have to go check on his grandma, jack is glad she is dead. And in the history echos, it explains that jack was raised by his VERY ABUSIVE grandmother. She could have been the one who beat him and blinded him and eventually 'branded' him with a vault symbol. But i will admit that the comment about him being in the cult of the vault is very plausible too since you have to find all of the markings, and after all he is desperately wanting the vault to open for him.

Jack mentions that he knows of three livingsirens (Lilith, Maya and Angel, with Steele being omitted because she died during the events of BL1), and that only six sirens can exist at once. However, Jack loves to "keep secrets hidden in plain sight"; it's likely that he omitted the fact that he's a male siren because male sirens are not called sirens (which is highly plausible considering that BL has a history of keeping thinly veiled secrets about main characters, notably Steele). It's also perfectly possible that there can be six sirens and six male sirens in existence at the same time.

Evidence pointing to the fact that Jack is a male siren:

1. The vault symbol on his face is identical, in color and glow, to the sirens' "tattoos".2. His melee attack is identical to that used by Lilith and Maya.3. He can teleport and phasewalk.4. In roman mythology, the brother of sirens is a monstrous serpent (Jack displays "monstrous" and "serpentine"/manipulative traits, and is even referred to as a "monster" in-game).

Jack mentions that he knows of three living sirens (Lilith, Maya and Angel, with Steele being omitted because she died during the events of the first game), and that only six sirens can exist at once. However, Jack loves to toy with his victims by keeping secrets which he reveals only at the last minute (i.e. shield core, Wilhelm); it's likely that he omitted the fact that he's a siren until he reveals himself as such when attacking the vault hunter (which is highly plausible considering that Borderlands has a history of veiling such information about main characters until it is revealed in climactic a cutscene or during gameplay, notably in the case of Commandant Steele).

Strong evidence pointing to the fact that Jack is a male siren:

1. The vault symbol on his face is identical, in color and glow, to the sirens' "tattoos". 2. His melee attack is identical to that used by Lilith and Maya. 3. He can teleport and make use of an ability which strongly resembles Lilith's phasewalk. 4. In roman mythology, the brother of sirens is a monstrous serpent (Jack displays "monstrous" and "serpentine"/manipulative traits, and is referred to as a "monster" in-game).

Interesting note: Jack's wrist "tattoo" is virtually identical in color to Commandant Steele's body "tattoos", and appears to be a more masculine (angular) version of the sirens' (rounded) "tattoos".

Jack mentions that he knows of three living sirens (Lilith, Maya and Angel, with Steele being omitted because she died during the events of the first game), and that only six sirens can exist at once. However, Jack loves to toy with his victims by keeping secrets which he reveals only at the last minute (i.e. shield core, Wilhelm); it's likely that he omitted the fact that he's a siren until he reveals himself as such when attacking the vault hunter (which is highly plausible considering that Borderlands has a history of veiling such information about main characters until it is revealed in climactic a cutscene or during gameplay, notably in the case of Commandant Steele).

Strong evidence pointing to the fact that Jack is a male siren:

1. The vault symbol on his face is identical, in color and glow, to the sirens' "tattoos". 2. His melee attack is identical to that used by Lilith and Maya. 3. He can teleport and make use of an ability which strongly resembles Lilith's phasewalk. 4. In roman mythology, the brother of sirens is a monstrous serpent (Jack displays "monstrous" and "serpentine"/manipulative traits, and is referred to as a "monster" in-game).

Interesting note: Jack's wrist "tattoo" is virtually identical in color to Commandant Steele's body "tattoos", and appears to be a more masculine (angular) version of the sirens' (rounded) "tattoos".